With the development of economic globalization and the demands for mobile, wireless and multimedia communications, all kinds of wireless communication have been developed vigorously. Currently, seven or more standards or frequency bands are applied in the wireless communications, and each standard has unique characteristics and restrictions; however, after entering into the 4 G standard in 2010 and the 5 G standard in 2020 in future, the development of the broadband communication technology is in a trend of making full use of the undeveloped or less applied frequency resources (such as the operating frequency band of 2.4 G, 3.5 G, 5.7 G, 26 G, 30 G, 38 G or even 60 G) to realize a high access rate.
The conventional electronic elements are big and have high insertion loss and consumption power, so these electronic elements are certainly hard to meet the future demands for high-frequency elements. As compared with the prior art, regarding the RF frequency band, only the MEMS element can provide sufficient isolation and very low insertion loss. In order to satisfy the operating frequency and power loss requirements of future wireless communication systems, the “light, thin, short and small” and low-loss MEMS element may be fabricated through the MEMS technology.
A greater frequency spectrum utilization rate may be realized by integrating the advanced technologies in the field of microwave and wired communications. Therefore, the microwave switch fabricated through the MEMS process is one of the critical technologies of the practicability of 4 G and 5 G. However, it is the challenge for us today to integrate the frequency bands so as to achieve more flexible bandwidth distribution.